HEATED SOX have been designed to keep your feet warm during the cold winter months.HEATED Socks have been tested to achieve a thermal tog rating of 2.13, and will keep your feet warmer to minus -25C or -13F ensuring your feet stay warmer for longer. a high tog rating provides extra insulation against low temperatures. THIS IS HOW HEATED SOX WORK: 1.High bulk acrylic yarn. Reinforced heel&toe for extra durability. 2. New antibacterial treatment to keep your feet fresh&odor free. 3.brushed inside. Comfort toe seam to reduce abrasion&improve comfort. 4. Moisture control to keep feet dry..